iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index() Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index() where shifting the constant "1" (of type int) by bitmap->mapped.pgshift (an unsigned long value) could result in undefined behavior. The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds 31 (e.g., pgshift = 63) the shift operation overflows, as the result cannot be represented in a 32-bit type. To resolve this, the constant is updated to "1UL", promoting it to an unsigned long type to match the operand's type.

References

• https://git.kernel.org/stable/c/44d9c94b7a3f29a3e07c4753603a35e9b28842a3
• https://git.kernel.org/stable/c/38ac76fc06bc6826a3e4b12a98efbe98432380a9
• https://git.kernel.org/stable/c/d5d33f01b86af44b23eea61ee309e4ef22c0cdfe
• https://git.kernel.org/stable/c/b1f8453b8ff1ab79a03820ef608256c499769cb6
• https://git.kernel.org/stable/c/e24c1551059268b37f6f40639883eafb281b8b9c